Matt Yglesias makes the point that "a majority of Senators “can” do pretty much whatever it likes."
Well, yes, but. There are two reasons it's not apt to happen.
First, on this bill. What's likely going on, again, are two things: a desire to get a bill, and a desire to avoid controversial votes. The latter increases as we get closer to the 60th Senator. Senators seeking to avoid a controversial vote are looking to establish markers of reasonableness in lieu of Republican votes, which are essentially unavailable.
Violating norms or changing rules to allow a simple majority to work its will is the last thing that those Senators want, because the resulting bill will certainly be seen as controversial by Washingtonians, including the media. Instead, they are looking for the lowest realistic conditions of controversy available, which appear to include prolonged negotiations, unified Democratic support, and the support of at least the Maine Senators and possibly one other GOP vote. Bullying, then, will be a viable strategy if there are at least fifty Democratic Senators who are willing to support a bill under conditions of maximum controversy, but not fifty-eight (or maybe fifty-seven) Democrats willing to support a bill under the least foreseeable conditions of controversy. It is possible that we'll wind up in that range, but I suspect that it is unlikely.
More broadly, Senators have always found it within their interests to preserve the power of individual members of the upper chamber. That's the nature of the body, thanks to the relatively small number of Senators and the relatively diverse interests of statewide districts. On balance, I think that's a worthwhile function of the Senate within the system. Moreover, while I think it's fair to say that across-the-board, automatic filibusters on every issue are problematic, additional rights for the minority on major issues are well within the tradition of the Senate, and the health care bill fits comfortably within that. At any rate, good thing or no, it's built into the structure of the Senate and therefore unlikely to change from within.